The head of a conventional toothbrush usually has a flat or slightly altered surface to which cleaning elements are attached. Usually the cleaning elements are strands of plastic material(s) formed into tufts, bundles or other groupings. The strands are attached to the head either before or after forming the toothbrush.
Various approaches have been advanced in the prior art for orientating the cleaning elements in the toothbrush.
U.S. Pat. No. 2,083,217 issued Jun. 8, 1937 to E. I. Brothers, et al. discloses two or three circular brush sections which are arranged within cups 5 and 5′ that may be screwed into mating receptacles in the tooth brush handle so that they can be removed and replaced as needed (page 2, lines 52-70). Each brush section contains stiff cleaning elements and is spaced from the other along the longitudinal axis of the handle at a distance less than the thickness of a tooth so that the brush operates on both the lingual (inside) and facial (outside) surfaces of the teeth (page 2, column 1, line 71 to column 2, line 9).
U.S. Pat. No. 5,604,951 describes a toothbrush with a head containing a flexible, rubber-like prophylaxis polishing cup or “prophy cup” similar to that used by dental personnel to professionally clean teeth. This prophy cup is loaded with toothpaste by the user and applied to the teeth. According to this patent, the “soft rubber-like prophy cup device follows the contours of teeth more effectively than bristles” (column 2, lines 23-26). This patent also discloses a ring of cleaning elements (“bristle tufts”) placed about the periphery of the toothbrush head which coact with the prophy cups to clean the user's teeth and gums (column 2, lines 34-47).
Another approach to oral hygiene is described in the toothbrush described in U.S. Pat. No. 6,041,468 issued to the assignee of this application. The cleaning elements (bristles) of this toothbrush are arranged in a concave shape across the width of the toothbrush head (See FIGS. 3-5 and column 4, lines 1-22).
Design Patents illustrating circular groups of cleaning elements are U.S. Pat. Nos. Des. 273,635 issued May 1, 1984 to Stocchi and D450,929S issued Nov. 27, 2001 to Angelina, et al.